/*
 * Copyright (c) 2023. Baidu, Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *    http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and limitations under the License.
 */

package com.baidu.bifromq.basekv.localengine.rocksdb;

import com.baidu.bifromq.basekv.localengine.IKVSpaceCheckpoint;
import java.util.Optional;
import org.rocksdb.ColumnFamilyDescriptor;
import org.rocksdb.ColumnFamilyHandle;
import org.rocksdb.RocksDB;

/**
 * We leave snapshot based checkpoint mechanism here as a reference
 */
class RocksDBSnapshotableKVSpace extends RocksDBKVSpace {
    public RocksDBSnapshotableKVSpace(String id, ColumnFamilyDescriptor cfDesc,
                                      ColumnFamilyHandle cfHandle, RocksDB db,
                                      RocksDBKVEngineConfigurator configurator, RocksDBKVEngine engine,
                                      Runnable onDestroy,
                                      String... tags) {
        super(id, cfDesc, cfHandle, db, configurator, engine, onDestroy, tags);
    }

    @Override
    protected IRocksDBKVSpaceCheckpoint doCheckpoint() {
        doFlush();
        RocksDBKVSpaceSnapshot cp = new RocksDBKVSpaceSnapshot(id, db.getSnapshot(), cfHandle, db);
        Optional<IKVSpaceCheckpoint> existing = open(cp.cpId());
        if (existing.isPresent()) {
            cp.close();
            return (IRocksDBKVSpaceCheckpoint) existing.get();
        }
        return cp;
    }

    @Override
    protected IRocksDBKVSpaceCheckpoint doLoadLatestCheckpoint() {
        return doCheckpoint();
    }
}
